The invention is relative to a device for manipulating a yarn end of a textile package for preparation thereof for unwinding, and more particularly to a the yarn manipulating device comprising a yarn-end receiving member connected to a vacuum system.
Such yarn manipulating devices are known in various embodiments in conjunction with textile machines which produce cross-wound bobbins and are explained in detail in numerous protective-right references.
German Patent Publications DE 39 25 861 A1 and DE 40 09 702 A1 describe by way of example yarn manipulating devices in the form of so-called preparation devices. The spinning cops finished on ring spinning machines connected in series are pretreated in such a manner on such preparation devices that they can be readily rewound to large-volume cross-wound bobbins subsequently at the winding heads of automatic cheese winders. The preparation devices are components of a transport system for spinning cops and empty tubes in a bobbin winding machine and have, among other things, a yarn-end loosening and receiving device, preferably in the form of a suction nozzle, connected to a waste collector. In addition, a pneumatic air blocking device and, normally, a yarn separating device are located in the area of the yarn-end loosening and receiving device.
The suction nozzle has a mouth area which is approximately adapted to the outer contour of the spinning cops and often comprises an intake slot extending over the entire length of the cop. The suction nozzle takes the yarn at first from the cop surface, cuts it to length by the yarn separating device and places it thereafter back on the cop surface or on the tip or nose of the tube in such a manner that it is disposed to be readily taken up for a subsequent work step.
The normal air requirement of these known preparation devices is not insignificant and is held within limits by an air blocking device which only connects the suction nozzle of the preparation device to the vacuum system of the textile machine if a spinning cop is ready on the preparation device.
A so-called residual cop preparation device which is comparable as regards the manner of operation is known from German Patent Publication DE 195 19 827 A1. In this residual cop preparation device the yarn-end receiving member comprises a relatively large-volume base housing connected via a vacuum line to a vacuum source. The base housing, in which a vacuum of approximately 60 to 90 mbar prevails in the operating state, comprises a vertical suction intake slot in the area of a frontal, convexly curved wall which slot has approximately the length of a spinning cop. Deflection elements are arranged on the top and/or the bottom of the housing over which elements travels a sealing belt which comprises an air passage opening with a suction nozzle connected in series. The sealing belt can be positioned in such a manner in a neutral or starting position that the intake slot is completely sealed; that is, the air passage opening is then positioned above the intake slot. The sealing belt can be lowered from this neutral position so that the suction nozzle can be brought continuously into operating positions of differing heights. A regulatable yarn separating device is also positioned here in the area of the suction-air connection of the base housing which separating device makes possible a defined cutting to length of the received yarn end.
However, a disadvantage of the known yarn manipulating devices is the fact that the operating elements arranged in a housing-like covering, preferably the air-blocking device designed as an air aperture and/or the yarn cutting device, and the areas of the housing-like covering not directly lying in the flow of suction air are very susceptible to formation of fluff or fly. Therefore, it is not uncommon that the proper functioning of the operating elements of such yarn manipulating devices is affected after a relatively short time already.